The present invention relates to an arrangement for providing access between a telecommunications station in a telecommunications network and a data network. The invention also relates to access support means supporting access between a computer connected to a telecommunications station and a data network and to a communication system in which access is provided between mobile and/or fixed telecommunication stations and a data network. Still further the invention relates to a method of sending data between a personal computer connected to a telecommunications station and a data network such as for example Internet, intranets, corporate LAN:s or external public data networks etc. The use of data networks is increasing rapidly worldwide. In particular the continued exponential growth of the Internet has created needs for development of new protocols, techniques and products for accessing Internet, particularly via cellular mobile telecommunications networks.
In general subscribers of cellular mobile telecommunications networks as well as fixed subscribers need to be able to access different data networks such as for example Internet, corporate LANs (Local Area Network), intranets and external public data networks etc.
Basically three different ways of accessing data networks, such as intranets or Internet, from cellular mobile communication systems, such as for example GSM (Global System for Mobile Communications), are known.
One way relates to a packet switched data service which currently has been standardized for a later implementation in the GSM system. This is called the General Packet Radio Service (GPRS). This packet switched data service allows packet switched communications such as for example virtual circuit switched communication or IP (Internet Protocol) communication. GPRS is currently being standardized by the European Telecommunications Standards Institute (ETSI), but it is not yet in service.
Another way of accessing a data network is through the use of the Short Message Service (SMS). SMS provides a connection-less transfer of messages, the messages being stored and forwarded by an SMS-service center. The short messages are transported on the signalling links of the telecommunications system. However, the capacity is low (160 bytes in each message) and the time performance is also low. For example it takes about 3 seconds to reach the mobile from a SMS-service center. SMS is optimized for short messages and notifications and a more extended use of SMS for packet data applications would severely load the signalling links or the signalling networks of the cellular mobile communication system, such as for example GSM.
Still another way of accessing data networks from GSM relates to a new application solution intending to enhance the existing GSM data services, the so called xe2x80x9cIP Direct Accessxe2x80x9d which is a type of GSM bearer services. This is a dial-up (mobile-originated only) circuit-switched service with TCP/IP (Transmission Control Protocol/Internet Protocol) based inter-networking. Direct Access means that the circuit-switched part of the GSM data call within the PLMN (Public Land Mobile Network) is not routed through a public ISDN (Integrated Services Digital Network) or PSTN (Public Switched Telecommunications Network) but instead it is terminated at a LAN (Local Area Network) or a WAN (Wide Area Network) for further transportation of data traffic to external data networks. Thus direct access is provided to servers in a LAN or in Internet.
However, it is a serious drawback that the xe2x80x9cIP Direct Accessxe2x80x9d method only allows mobile-originated service, i.e. dial-up, or nothing. Another serious drawback with this method is that a connection will be used for the total duration of a session which means that the connection will be used also when no data actually is sent. This is a serious waste for the operator since radio resources are wasted. It is also a serious drawback for the user who has to pay for the duration of a call instead of for the data that has actually been sent, i.e. a charging method based on the volume of the sent data which would be very attractive for the customer. Still further the method provides for no mobility and roaming support between access points.
What is needed is therefore an arrangement for providing access between a telecommunications station in a telecommunications network and a data network which enables a high capacity transfer of messages and which has a high time performance. An arrangement is also needed which enables data access for mobile as well as for fixed subscribers through which the radio resources are efficiently used and which is cost-efficient for the user. Still further an arrangement is needed which enables a mobile originated service as well as a mobile terminated service. Particularly an arrangement is needed which provides for mobility and roaming support between access points.
A communication system is also needed in which access between a subscriber station of a telecommunications network, a mobile station or a fixed station, and a data network is provided in which the radio resources are efficiently used and in which larger amounts of data can be sent with a high capacity and a high performance, and without loading the signalling links of the system. A communication system is also needed through which mobile originated services as well as mobile terminated services are enabled. Still further a communication system is needed in which mobility and roaming support between access points is provided.
A method of providing access between a mobile or a fixed telecommunications station and a data network is also needed through which the above mentioned objects are achieved.
An arrangement as referred to above is therefore provided which comprises access support means which are connected to a server, via which a connection can be set-up between a telecommunications station and a data network. When a telecommunications station is registered with the access support means, the access support means can switch the telecommunications station between a connected mode, in which the telecommunications station is connected to the server, and an intermediate, or a semi-connected, mode in which the telecommunications station is still registered with the access support means but in which it is disconnected from the server, in such a way that the telecommunications station only is in the connected mode when data actually is sent to/from the telecommunications station.
The server may e.g. be a so called point-to-point protocol server, PPP-server, which uses a point-to-point protocol (PPP) which relates to a standard method for transporting multi-protocol datagrams over point-to-point links. The point-to-point protocol is designed for simple links transporting packets between two peers, a peer being one of two ends of a point-to-point link. These links provide for full duplex, simultaneous bi-directional operation and they are assumed to deliver packets in order. PPP is a known solution intended to provide an easy connection of a large number of, and a wide variety of, hosts, bridges and routers. A router in this context is a node which forwards IP packets not explicitly addressed to the node itself and a host is any node which is not a router. These as well as other concepts, which will be further discussed below, are among others discussed in xe2x80x9cIP Mobility Supportxe2x80x9d, C. Perkins, editor IBM, October 1996, The Network Working Group, pages 1-12, xe2x80x9cThe point-to-point protocol (PPP)xe2x80x9d, W. Simpson, editor Daydreamer, July 1994, up to page 9 and xe2x80x9cMobility Support in IPv6xe2x80x9d, David B. Johnson, Carnegie Mellon University, Charles Perkins IBM Corporation, Nov. 26, 1996, up to page 8. These documents are herewith incorporated herein by reference.
In an advantageous embodiment the telecommunications station is automatically registered with the access support means when it is connected to the server, e.g. the PPP-server, i.e. when it is connected to the data network. In an alternative embodiment the telecommunications station is registered with the access support means through the user giving a command for registration with the access support means. According to one embodiment the length of the periods of semi-connection, i.e. the length of the periods spent in the intermediate mode, is preset or it can be given, e.g. in the command for semi-connection. Particularly the lengths of the semi-connection periods are adjustable, or can be varied in one way or another.
Advantageously the telecommunications station is registered with the access support means using its address, its telephone number and its identification. However, this can be done in different manners and it also depends on whether the telecommunications station is a fixed station or a mobile station.
In an advantageous embodiment the access support means switches the telecommunications station from the semi-connected mode, i.e. the intermediate mode, to the connected mode without requiring any action from the user or from the telecommunications station (or the data network), particularly without requiring the giving of any user identification or password etc.
If a registration request, which either may come from the telecommunications station or from an gent in a data network with which the telecommunications station is registered, is received in the access support means, the telecommunications station is advantageously switched to a disconnected mode.
According to an advantageous embodiment the access support means comprises storing means for storing data packets sent to/from a telecommunications station during the semi-connection mode, which packets are arranged in packet blocks of a given length, which blocks comprise a number of packets. The block length is advantageously adjustable depending on the system, the needs, the current circumstances etc. The data packets are sent to the telecommunications station blockwise during the connected mode and the radio resources are only used when the data is sent and the data is sent blockwise in any convenient manner.
In an advantageous embodiment, e.g. relating to Internet, the access support means sets up an association between the Internet Protocol IP-address in a foreign agent of the data network with which the telecommunications station is registered and the (point-to-point) server.
The Internet Protocol provides for a mobility supporting functionality. Therefore a mobile node has been introduced. A mobile node is a host or a router which changes its point of attachment from one network, or subnetwork, to another. A mobile node can change its location without changing its IP-address and it can continue to communicate with other internet nodes at any location using its xe2x80x9cnormalxe2x80x9d IP-address. A home agent is a router on a mobile node""s home network which tunnels packets for delivery to the mobile node when it is away from home, and maintains current location information for the mobile node.
A foreign agent is a router on a mobile node""s visited network which provides routing services to the mobile node as long as it is registered. The foreign agent detunnels and delivers packets to the mobile node which were tunneled by the mobile node""s home agent. For packets, or datagrams, sent by a mobile node, the foreign agent may serve as a default route for registered mobile nodes.
A mobile node is given a long term IP-address and a home network. The home address is administrated in the same way as a permanent IP-address is provided to a stationary host. When away from its home network, a care-of address is associated with the mobile node and reflects the current attachment point of the mobile node.
According to an advantageous embodiment of the invention, a terminal, i.e. a telecommunications station, which is handovered from another network, is registered in the access support means.
Advantageously a telecommunications station is switched into the connected mode and called up when needed by the access support means, for example when a block of packets is full.
In a particular embodiment the access support means control traffic to a telecommunications station from e.g. a foreign agent of the data network to the server, e.g. a PPP-server.
The data networks referred to in the application may for example be Internet, corporate local area networks LAN, an intranet or an external public data network or any other data network.
According to one embodiment the telecommunications station is a fixed station communicating with the (PPP-) server, for example over an ISDN-link or some other telephony link.
In another embodiment of the invention the telecommunications station comprises a mobile station of a mobile cellular communications system such as for example GSM. Other examples are ADC (American Digital Cellular), (D)-AMPS ((Digital)-Advanced Mobile Phone System), PDC (Pacific Digital Cellular) or any other cellular systems.
According to an advantageous embodiment location access means are provided which communicate with a home location register in which the mobile station is registered to provide the access support means with information about the current location of the mobile station.
Access support means are also provided which support access between a computer connected to a telecommunications station and a data network. The access support means are connected to a data network, for example via a server providing connection between the telecommunications station and the data network. The access support means further comprises means for registering a telecommunications station. A telecommunications station which is registered with the access support means is connected to the server only when data is sent to/from the telecommunications station, and, when no data traffic flows, the telecommunications station is switched to an intermediate mode in which it is disconnected from the server.
Advantageously the access support means comprises storing means for storing data packets into blocks of a desired length during the intermediate mode in which the fixed/mobile station is not connected to the server but merely registered with the access support means and data is sent to/from the telecommunications station in blocks, the length of the blocks preferably being adjustable. Advantageously a fast connection is established with the server without requiring any user identification etc. when it is time for sending a block with data, for example when the block is full or when the predefined time, if such limit has been set, for remaining in the intermediate mode has elapsed.
Particularly the access support means comprises a function block which is arranged between the server and mobility support agents provided in the data network or connected to the data network. Still further the access support means may be integrated with the server and/or mobility support agent(s).
Therefore also a communication system is provided in which access is provided between mobile and/or fixed telecommunications stations and a data network. Access support means are arranged between at least a number of servers providing communication between a number of telecommunications stations and the data network and mobility support agents provided in the system, which communicate with the respective servers. Alternatively the access support means are integrated with the server or with a mobility support agent. Still further the access support means, the server and the mobility support agent may all be integrated. Thus the functionality of the access support means can be implemented in different ways.
The access support means switch telecommunications stations registered with said access support means between a connected mode in which the telecommunications stations are connected to a server (e.g. a PPP-server) and an intermediate mode in which the telecommunications stations are registered with the access support means but in which they are disconnected from said server. The connected mode is only used when data is actually sent to/from said telecommunications stations. Particularly the sending is controlled in so far as data packets are received and arranged into blocks of data packets and the data is sent on from the access support means blockwise.
A method of sending data between a personal computer connected to a telecommunications station and a network, such as for example Internet, an intranet, external public data networks etc. is also provided which comprises the steps of; setting up a connection between a telecommunications station and the data network via a server, e.g. a PPP-server, registering the telecommunications station with access support means connected to or integrated with the server, switching the telecommunications station to an intermediate mode in which the telecommunications station remains registered with the access support means but in which it is disconnected from the server during sessions when no data traffic flows or while data is arranged in blocks of data packets in the access support means and, switching the telecommunications station to a connected mode in which it is connected to the server when data is sent. In this way the telecommunications station only is connected to the server when data actually is sent to or from the telecommunications station. Advantageously packetized data is stored into block in the access support means during the intermediate mode and data is only sent at given occassions or when a block is full. Advantageously the access support means switches the telecommunications station from the intermediate mode to the connected mode in a fast way without requiring any user identifying information or similar. According to different embodiments the telecommunications station is automatically registered with the access support means when it is switched on or alternatively a command has to be given to provide for registration with the access support means.